[mirror_ubuntu-zesty-kernel.git] / kernel / power / suspend.c

/*
 * kernel/power/suspend.c - Suspend to RAM and standby functionality.
 *
 * Copyright (c) 2003 Patrick Mochel
 * Copyright (c) 2003 Open Source Development Lab
 * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
 *
 * This file is released under the GPLv2.
 */

#include <linux/string.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/console.h>
#include <linux/cpu.h>
#include <linux/cpuidle.h>
#include <linux/syscalls.h>
#include <linux/gfp.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <linux/suspend.h>
#include <linux/syscore_ops.h>
#include <linux/ftrace.h>
#include <trace/events/power.h>
#include <linux/compiler.h>
#include <linux/moduleparam.h>

#include "power.h"

const char *pm_labels[] = { "mem", "standby", "freeze", NULL };
const char *pm_states[PM_SUSPEND_MAX];

unsigned int pm_suspend_global_flags;
EXPORT_SYMBOL_GPL(pm_suspend_global_flags);

static const struct platform_suspend_ops *suspend_ops;
static const struct platform_freeze_ops *freeze_ops;
static DECLARE_WAIT_QUEUE_HEAD(suspend_freeze_wait_head);

enum freeze_state __read_mostly suspend_freeze_state;
static DEFINE_SPINLOCK(suspend_freeze_lock);

void freeze_set_ops(const struct platform_freeze_ops *ops)
{
	lock_system_sleep();
	freeze_ops = ops;
	unlock_system_sleep();
}

static void freeze_begin(void)
{
	suspend_freeze_state = FREEZE_STATE_NONE;
}

static void freeze_enter(void)
{
	spin_lock_irq(&suspend_freeze_lock);
	if (pm_wakeup_pending())
		goto out;

	suspend_freeze_state = FREEZE_STATE_ENTER;
	spin_unlock_irq(&suspend_freeze_lock);

	get_online_cpus();
	cpuidle_resume();

	/* Push all the CPUs into the idle loop. */
	wake_up_all_idle_cpus();
	pr_debug("PM: suspend-to-idle\n");
	/* Make the current CPU wait so it can enter the idle loop too. */
	wait_event(suspend_freeze_wait_head,
		   suspend_freeze_state == FREEZE_STATE_WAKE);
	pr_debug("PM: resume from suspend-to-idle\n");

	cpuidle_pause();
	put_online_cpus();

	spin_lock_irq(&suspend_freeze_lock);

 out:
	suspend_freeze_state = FREEZE_STATE_NONE;
	spin_unlock_irq(&suspend_freeze_lock);
}

void freeze_wake(void)
{
	unsigned long flags;

	spin_lock_irqsave(&suspend_freeze_lock, flags);
	if (suspend_freeze_state > FREEZE_STATE_NONE) {
		suspend_freeze_state = FREEZE_STATE_WAKE;
		wake_up(&suspend_freeze_wait_head);
	}
	spin_unlock_irqrestore(&suspend_freeze_lock, flags);
}
EXPORT_SYMBOL_GPL(freeze_wake);

static bool valid_state(suspend_state_t state)
{
	/*
	 * PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states need low level
	 * support and need to be valid to the low level
	 * implementation, no valid callback implies that none are valid.
	 */
	return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
}

/*
 * If this is set, the "mem" label always corresponds to the deepest sleep state
 * available, the "standby" label corresponds to the second deepest sleep state
 * available (if any), and the "freeze" label corresponds to the remaining
 * available sleep state (if there is one).
 */
static bool relative_states;

void __init pm_states_init(void)
{
	/*
	 * freeze state should be supported even without any suspend_ops,
	 * initialize pm_states accordingly here
	 */
	pm_states[PM_SUSPEND_FREEZE] = pm_labels[relative_states ? 0 : 2];
}

static int __init sleep_states_setup(char *str)
{
	relative_states = !strncmp(str, "1", 1);
	return 1;
}

__setup("relative_sleep_states=", sleep_states_setup);

/**
 * suspend_set_ops - Set the global suspend method table.
 * @ops: Suspend operations to use.
 */
void suspend_set_ops(const struct platform_suspend_ops *ops)
{
	suspend_state_t i;
	int j = 0;

	lock_system_sleep();

	suspend_ops = ops;
	for (i = PM_SUSPEND_MEM; i >= PM_SUSPEND_STANDBY; i--)
		if (valid_state(i)) {
			pm_states[i] = pm_labels[j++];
		} else if (!relative_states) {
			pm_states[i] = NULL;
			j++;
		}

	pm_states[PM_SUSPEND_FREEZE] = pm_labels[j];

	unlock_system_sleep();
}
EXPORT_SYMBOL_GPL(suspend_set_ops);

/**
 * suspend_valid_only_mem - Generic memory-only valid callback.
 *
 * Platform drivers that implement mem suspend only and only need to check for
 * that in their .valid() callback can use this instead of rolling their own
 * .valid() callback.
 */
int suspend_valid_only_mem(suspend_state_t state)
{
	return state == PM_SUSPEND_MEM;
}
EXPORT_SYMBOL_GPL(suspend_valid_only_mem);

static bool sleep_state_supported(suspend_state_t state)
{
	return state == PM_SUSPEND_FREEZE || (suspend_ops && suspend_ops->enter);
}

static int platform_suspend_prepare(suspend_state_t state)
{
	return state != PM_SUSPEND_FREEZE && suspend_ops->prepare ?
		suspend_ops->prepare() : 0;
}

static int platform_suspend_prepare_late(suspend_state_t state)
{
	return state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->prepare ?
		freeze_ops->prepare() : 0;
}

static int platform_suspend_prepare_noirq(suspend_state_t state)
{
	return state != PM_SUSPEND_FREEZE && suspend_ops->prepare_late ?
		suspend_ops->prepare_late() : 0;
}

static void platform_resume_noirq(suspend_state_t state)
{
	if (state != PM_SUSPEND_FREEZE && suspend_ops->wake)
		suspend_ops->wake();
}

static void platform_resume_early(suspend_state_t state)
{
	if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->restore)
		freeze_ops->restore();
}

static void platform_resume_finish(suspend_state_t state)
{
	if (state != PM_SUSPEND_FREEZE && suspend_ops->finish)
		suspend_ops->finish();
}

static int platform_suspend_begin(suspend_state_t state)
{
	if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->begin)
		return freeze_ops->begin();
	else if (suspend_ops && suspend_ops->begin)
		return suspend_ops->begin(state);
	else
		return 0;
}

static void platform_resume_end(suspend_state_t state)
{
	if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->end)
		freeze_ops->end();
	else if (suspend_ops && suspend_ops->end)
		suspend_ops->end();
}

static void platform_recover(suspend_state_t state)
{
	if (state != PM_SUSPEND_FREEZE && suspend_ops->recover)
		suspend_ops->recover();
}

static bool platform_suspend_again(suspend_state_t state)
{
	return state != PM_SUSPEND_FREEZE && suspend_ops->suspend_again ?
		suspend_ops->suspend_again() : false;
}

#ifdef CONFIG_PM_DEBUG
static unsigned int pm_test_delay = 5;
module_param(pm_test_delay, uint, 0644);
MODULE_PARM_DESC(pm_test_delay,
		 "Number of seconds to wait before resuming from suspend test");
#endif

static int suspend_test(int level)
{
#ifdef CONFIG_PM_DEBUG
	if (pm_test_level == level) {
		pr_info("suspend debug: Waiting for %d second(s).\n",
				pm_test_delay);
		mdelay(pm_test_delay * 1000);
		return 1;
	}
#endif /* !CONFIG_PM_DEBUG */
	return 0;
}

/**
 * suspend_prepare - Prepare for entering system sleep state.
 *
 * Common code run for every system sleep state that can be entered (except for
 * hibernation).  Run suspend notifiers, allocate the "suspend" console and
 * freeze processes.
 */
static int suspend_prepare(suspend_state_t state)
{
	int error, nr_calls = 0;

	if (!sleep_state_supported(state))
		return -EPERM;

	pm_prepare_console();

	error = __pm_notifier_call_chain(PM_SUSPEND_PREPARE, -1, &nr_calls);
	if (error) {
		nr_calls--;
		goto Finish;
	}

	trace_suspend_resume(TPS("freeze_processes"), 0, true);
	error = suspend_freeze_processes();
	trace_suspend_resume(TPS("freeze_processes"), 0, false);
	if (!error)
		return 0;

	suspend_stats.failed_freeze++;
	dpm_save_failed_step(SUSPEND_FREEZE);
 Finish:
	__pm_notifier_call_chain(PM_POST_SUSPEND, nr_calls, NULL);
	pm_restore_console();
	return error;
}

/* default implementation */
void __weak arch_suspend_disable_irqs(void)
{
	local_irq_disable();
}

/* default implementation */
void __weak arch_suspend_enable_irqs(void)
{
	local_irq_enable();
}

/**
 * suspend_enter - Make the system enter the given sleep state.
 * @state: System sleep state to enter.
 * @wakeup: Returns information that the sleep state should not be re-entered.
 *
 * This function should be called after devices have been suspended.
 */
static int suspend_enter(suspend_state_t state, bool *wakeup)
{
	int error;

	error = platform_suspend_prepare(state);
	if (error)
		goto Platform_finish;

	error = dpm_suspend_late(PMSG_SUSPEND);
	if (error) {
		pr_err("PM: late suspend of devices failed\n");
		goto Platform_finish;
	}
	error = platform_suspend_prepare_late(state);
	if (error)
		goto Devices_early_resume;

	error = dpm_suspend_noirq(PMSG_SUSPEND);
	if (error) {
		pr_err("PM: noirq suspend of devices failed\n");
		goto Platform_early_resume;
	}
	error = platform_suspend_prepare_noirq(state);
	if (error)
		goto Platform_wake;

	if (suspend_test(TEST_PLATFORM))
		goto Platform_wake;

	/*
	 * PM_SUSPEND_FREEZE equals
	 * frozen processes + suspended devices + idle processors.
	 * Thus we should invoke freeze_enter() soon after
	 * all the devices are suspended.
	 */
	if (state == PM_SUSPEND_FREEZE) {
		trace_suspend_resume(TPS("machine_suspend"), state, true);
		freeze_enter();
		trace_suspend_resume(TPS("machine_suspend"), state, false);
		goto Platform_wake;
	}

	error = disable_nonboot_cpus();
	if (error || suspend_test(TEST_CPUS))
		goto Enable_cpus;

	arch_suspend_disable_irqs();
	BUG_ON(!irqs_disabled());

	error = syscore_suspend();
	if (!error) {
		*wakeup = pm_wakeup_pending();
		if (!(suspend_test(TEST_CORE) || *wakeup)) {
			trace_suspend_resume(TPS("machine_suspend"),
				state, true);
			error = suspend_ops->enter(state);
			trace_suspend_resume(TPS("machine_suspend"),
				state, false);
			events_check_enabled = false;
		} else if (*wakeup) {
			error = -EBUSY;
		}
		syscore_resume();
	}

	arch_suspend_enable_irqs();
	BUG_ON(irqs_disabled());

 Enable_cpus:
	enable_nonboot_cpus();

 Platform_wake:
	platform_resume_noirq(state);
	dpm_resume_noirq(PMSG_RESUME);

 Platform_early_resume:
	platform_resume_early(state);

 Devices_early_resume:
	dpm_resume_early(PMSG_RESUME);

 Platform_finish:
	platform_resume_finish(state);
	return error;
}

/**
 * suspend_devices_and_enter - Suspend devices and enter system sleep state.
 * @state: System sleep state to enter.
 */
int suspend_devices_and_enter(suspend_state_t state)
{
	int error;
	bool wakeup = false;

	if (!sleep_state_supported(state))
		return -ENOSYS;

	error = platform_suspend_begin(state);
	if (error)
		goto Close;

	suspend_console();
	suspend_test_start();
	error = dpm_suspend_start(PMSG_SUSPEND);
	if (error) {
		pr_err("PM: Some devices failed to suspend, or early wake event detected\n");
		goto Recover_platform;
	}
	suspend_test_finish("suspend devices");
	if (suspend_test(TEST_DEVICES))
		goto Recover_platform;

	do {
		error = suspend_enter(state, &wakeup);
	} while (!error && !wakeup && platform_suspend_again(state));

 Resume_devices:
	suspend_test_start();
	dpm_resume_end(PMSG_RESUME);
	suspend_test_finish("resume devices");
	trace_suspend_resume(TPS("resume_console"), state, true);
	resume_console();
	trace_suspend_resume(TPS("resume_console"), state, false);

 Close:
	platform_resume_end(state);
	return error;

 Recover_platform:
	platform_recover(state);
	goto Resume_devices;
}

/**
 * suspend_finish - Clean up before finishing the suspend sequence.
 *
 * Call platform code to clean up, restart processes, and free the console that
 * we've allocated. This routine is not called for hibernation.
 */
static void suspend_finish(void)
{
	suspend_thaw_processes();
	pm_notifier_call_chain(PM_POST_SUSPEND);
	pm_restore_console();
}

/**
 * enter_state - Do common work needed to enter system sleep state.
 * @state: System sleep state to enter.
 *
 * Make sure that no one else is trying to put the system into a sleep state.
 * Fail if that's not the case.  Otherwise, prepare for system suspend, make the
 * system enter the given sleep state and clean up after wakeup.
 */
static int enter_state(suspend_state_t state)
{
	int error;

	trace_suspend_resume(TPS("suspend_enter"), state, true);
	if (state == PM_SUSPEND_FREEZE) {
#ifdef CONFIG_PM_DEBUG
		if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
			pr_warn("PM: Unsupported test mode for suspend to idle, please choose none/freezer/devices/platform.\n");
			return -EAGAIN;
		}
#endif
	} else if (!valid_state(state)) {
		return -EINVAL;
	}
	if (!mutex_trylock(&pm_mutex))
		return -EBUSY;

	if (state == PM_SUSPEND_FREEZE)
		freeze_begin();

#ifndef CONFIG_SUSPEND_SKIP_SYNC
	trace_suspend_resume(TPS("sync_filesystems"), 0, true);
	printk(KERN_INFO "PM: Syncing filesystems ... ");
	sys_sync();
	printk("done.\n");
	trace_suspend_resume(TPS("sync_filesystems"), 0, false);
#endif

	pr_debug("PM: Preparing system for sleep (%s)\n", pm_states[state]);
	pm_suspend_clear_flags();
	error = suspend_prepare(state);
	if (error)
		goto Unlock;

	if (suspend_test(TEST_FREEZER))
		goto Finish;

	trace_suspend_resume(TPS("suspend_enter"), state, false);
	pr_debug("PM: Suspending system (%s)\n", pm_states[state]);
	pm_restrict_gfp_mask();
	error = suspend_devices_and_enter(state);
	pm_restore_gfp_mask();

 Finish:
	pr_debug("PM: Finishing wakeup.\n");
	suspend_finish();
 Unlock:
	mutex_unlock(&pm_mutex);
	return error;
}

/**
 * pm_suspend - Externally visible function for suspending the system.
 * @state: System sleep state to enter.
 *
 * Check if the value of @state represents one of the supported states,
 * execute enter_state() and update system suspend statistics.
 */
int pm_suspend(suspend_state_t state)
{
	int error;

	if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
		return -EINVAL;

	error = enter_state(state);
	if (error) {
		suspend_stats.fail++;
		dpm_save_failed_errno(error);
	} else {
		suspend_stats.success++;
	}
	return error;
}
EXPORT_SYMBOL(pm_suspend);
Commit	Line	Data
a9d70523 RW	1	/*
	2	* kernel/power/suspend.c - Suspend to RAM and standby functionality.
	3	*
	4	* Copyright (c) 2003 Patrick Mochel
	5	* Copyright (c) 2003 Open Source Development Lab
	6	* Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
	7	*
	8	* This file is released under the GPLv2.
	9	*/
	10
	11	#include <linux/string.h>
	12	#include <linux/delay.h>
	13	#include <linux/errno.h>
	14	#include <linux/init.h>
	15	#include <linux/console.h>
	16	#include <linux/cpu.h>
f3f12532	17	#include <linux/cpuidle.h>
a9d70523	18	#include <linux/syscalls.h>
5a0e3ad6	19	#include <linux/gfp.h>
dd4c4f17 MG	20	#include <linux/io.h>
	21	#include <linux/kernel.h>
	22	#include <linux/list.h>
	23	#include <linux/mm.h>
	24	#include <linux/slab.h>
6e5fdeed	25	#include <linux/export.h>
dd4c4f17	26	#include <linux/suspend.h>
40dc166c	27	#include <linux/syscore_ops.h>
443772d4	28	#include <linux/ftrace.h>
938cfed1	29	#include <trace/events/power.h>
52f5684c	30	#include <linux/compiler.h>
1d4a9c17	31	#include <linux/moduleparam.h>
a9d70523 RW	32
	33	#include "power.h"
	34
62109b43	35	const char *pm_labels[] = { "mem", "standby", "freeze", NULL };
d431cbc5	36	const char *pm_states[PM_SUSPEND_MAX];
a9d70523	37
ef25ba04 RW	38	unsigned int pm_suspend_global_flags;
	39	EXPORT_SYMBOL_GPL(pm_suspend_global_flags);
	40
2f55ac07	41	static const struct platform_suspend_ops *suspend_ops;
1f0b6386	42	static const struct platform_freeze_ops *freeze_ops;
7e73c5ae	43	static DECLARE_WAIT_QUEUE_HEAD(suspend_freeze_wait_head);
38106313 RW	44
	45	enum freeze_state __read_mostly suspend_freeze_state;
	46	static DEFINE_SPINLOCK(suspend_freeze_lock);
7e73c5ae	47
1f0b6386 RW	48	void freeze_set_ops(const struct platform_freeze_ops *ops)
	49	{
	50	lock_system_sleep();
	51	freeze_ops = ops;
	52	unlock_system_sleep();
	53	}
	54
7e73c5ae ZR	55	static void freeze_begin(void)
7e73c5ae ZR	56	{
38106313	57	suspend_freeze_state = FREEZE_STATE_NONE;
7e73c5ae ZR	58	}
	59
	60	static void freeze_enter(void)
	61	{
38106313 RW	62	spin_lock_irq(&suspend_freeze_lock);
	63	if (pm_wakeup_pending())
	64	goto out;
	65
	66	suspend_freeze_state = FREEZE_STATE_ENTER;
	67	spin_unlock_irq(&suspend_freeze_lock);
	68
	69	get_online_cpus();
f3f12532	70	cpuidle_resume();
38106313 RW	71
	72	/* Push all the CPUs into the idle loop. */
	73	wake_up_all_idle_cpus();
	74	pr_debug("PM: suspend-to-idle\n");
	75	/* Make the current CPU wait so it can enter the idle loop too. */
	76	wait_event(suspend_freeze_wait_head,
	77	suspend_freeze_state == FREEZE_STATE_WAKE);
	78	pr_debug("PM: resume from suspend-to-idle\n");
	79
f3f12532	80	cpuidle_pause();
38106313 RW	81	put_online_cpus();
	82
	83	spin_lock_irq(&suspend_freeze_lock);
	84
	85	out:
	86	suspend_freeze_state = FREEZE_STATE_NONE;
	87	spin_unlock_irq(&suspend_freeze_lock);
7e73c5ae ZR	88	}
	89
	90	void freeze_wake(void)
	91	{
38106313 RW	92	unsigned long flags;
	93
	94	spin_lock_irqsave(&suspend_freeze_lock, flags);
	95	if (suspend_freeze_state > FREEZE_STATE_NONE) {
	96	suspend_freeze_state = FREEZE_STATE_WAKE;
	97	wake_up(&suspend_freeze_wait_head);
	98	}
	99	spin_unlock_irqrestore(&suspend_freeze_lock, flags);
7e73c5ae ZR	100	}
	101	EXPORT_SYMBOL_GPL(freeze_wake);
	102
43e8317b RW	103	static bool valid_state(suspend_state_t state)
	104	{
	105	/*
	106	* PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states need low level
	107	* support and need to be valid to the low level
	108	* implementation, no valid callback implies that none are valid.
	109	*/
	110	return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
	111	}
	112
0399d4db RW	113	/*
	114	* If this is set, the "mem" label always corresponds to the deepest sleep state
	115	* available, the "standby" label corresponds to the second deepest sleep state
	116	* available (if any), and the "freeze" label corresponds to the remaining
	117	* available sleep state (if there is one).
	118	*/
	119	static bool relative_states;
	120
fa7fd6fa SH	121	void __init pm_states_init(void)
	122	{
	123	/*
	124	* freeze state should be supported even without any suspend_ops,
	125	* initialize pm_states accordingly here
	126	*/
	127	pm_states[PM_SUSPEND_FREEZE] = pm_labels[relative_states ? 0 : 2];
	128	}
	129
0399d4db RW	130	static int __init sleep_states_setup(char *str)
	131	{
	132	relative_states = !strncmp(str, "1", 1);
0399d4db RW	133	return 1;
	134	}
	135
	136	__setup("relative_sleep_states=", sleep_states_setup);
	137
a9d70523	138	/**
55ae4519 RW	139	* suspend_set_ops - Set the global suspend method table.
55ae4519 RW	140	* @ops: Suspend operations to use.
a9d70523	141	*/
2f55ac07	142	void suspend_set_ops(const struct platform_suspend_ops *ops)
a9d70523	143	{
43e8317b	144	suspend_state_t i;
d431cbc5	145	int j = 0;
43e8317b	146
bcda53fa	147	lock_system_sleep();
43e8317b	148
a9d70523	149	suspend_ops = ops;
0399d4db	150	for (i = PM_SUSPEND_MEM; i >= PM_SUSPEND_STANDBY; i--)
d431cbc5 RW	151	if (valid_state(i)) {
	152	pm_states[i] = pm_labels[j++];
	153	} else if (!relative_states) {
	154	pm_states[i] = NULL;
	155	j++;
	156	}
0399d4db	157
d431cbc5	158	pm_states[PM_SUSPEND_FREEZE] = pm_labels[j];
43e8317b	159
bcda53fa	160	unlock_system_sleep();
a9d70523	161	}
a5e4fd87	162	EXPORT_SYMBOL_GPL(suspend_set_ops);
a9d70523	163
a9d70523	164	/**
55ae4519	165	* suspend_valid_only_mem - Generic memory-only valid callback.
a9d70523	166	*
55ae4519 RW	167	* Platform drivers that implement mem suspend only and only need to check for
	168	* that in their .valid() callback can use this instead of rolling their own
	169	* .valid() callback.
a9d70523 RW	170	*/
	171	int suspend_valid_only_mem(suspend_state_t state)
	172	{
	173	return state == PM_SUSPEND_MEM;
	174	}
a5e4fd87	175	EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
a9d70523	176
8490fdf9 RW	177	static bool sleep_state_supported(suspend_state_t state)
	178	{
	179	return state == PM_SUSPEND_FREEZE \|\| (suspend_ops && suspend_ops->enter);
	180	}
	181
	182	static int platform_suspend_prepare(suspend_state_t state)
	183	{
	184	return state != PM_SUSPEND_FREEZE && suspend_ops->prepare ?
	185	suspend_ops->prepare() : 0;
	186	}
	187
a8d46b9e RW	188	static int platform_suspend_prepare_late(suspend_state_t state)
a8d46b9e RW	189	{
403b9636	190	return state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->prepare ?
a8d46b9e RW	191	freeze_ops->prepare() : 0;
	192	}
	193
ebc3e41e	194	static int platform_suspend_prepare_noirq(suspend_state_t state)
8490fdf9 RW	195	{
	196	return state != PM_SUSPEND_FREEZE && suspend_ops->prepare_late ?
	197	suspend_ops->prepare_late() : 0;
	198	}
	199
ebc3e41e	200	static void platform_resume_noirq(suspend_state_t state)
8490fdf9 RW	201	{
	202	if (state != PM_SUSPEND_FREEZE && suspend_ops->wake)
	203	suspend_ops->wake();
	204	}
	205
a8d46b9e RW	206	static void platform_resume_early(suspend_state_t state)
a8d46b9e RW	207	{
403b9636	208	if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->restore)
a8d46b9e RW	209	freeze_ops->restore();
	210	}
	211
ebc3e41e	212	static void platform_resume_finish(suspend_state_t state)
8490fdf9 RW	213	{
	214	if (state != PM_SUSPEND_FREEZE && suspend_ops->finish)
	215	suspend_ops->finish();
	216	}
	217
	218	static int platform_suspend_begin(suspend_state_t state)
	219	{
	220	if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->begin)
	221	return freeze_ops->begin();
fa7fd6fa	222	else if (suspend_ops && suspend_ops->begin)
8490fdf9 RW	223	return suspend_ops->begin(state);
	224	else
	225	return 0;
	226	}
	227
ebc3e41e	228	static void platform_resume_end(suspend_state_t state)
8490fdf9 RW	229	{
	230	if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->end)
	231	freeze_ops->end();
fa7fd6fa	232	else if (suspend_ops && suspend_ops->end)
8490fdf9 RW	233	suspend_ops->end();
	234	}
	235
ebc3e41e	236	static void platform_recover(suspend_state_t state)
8490fdf9 RW	237	{
	238	if (state != PM_SUSPEND_FREEZE && suspend_ops->recover)
	239	suspend_ops->recover();
	240	}
	241
	242	static bool platform_suspend_again(suspend_state_t state)
	243	{
	244	return state != PM_SUSPEND_FREEZE && suspend_ops->suspend_again ?
	245	suspend_ops->suspend_again() : false;
	246	}
	247
1d4a9c17 BN	248	#ifdef CONFIG_PM_DEBUG
	249	static unsigned int pm_test_delay = 5;
	250	module_param(pm_test_delay, uint, 0644);
	251	MODULE_PARM_DESC(pm_test_delay,
	252	"Number of seconds to wait before resuming from suspend test");
	253	#endif
	254
a9d70523 RW	255	static int suspend_test(int level)
	256	{
	257	#ifdef CONFIG_PM_DEBUG
	258	if (pm_test_level == level) {
22e09b33	259	pr_info("suspend debug: Waiting for %d second(s).\n",
1d4a9c17 BN	260	pm_test_delay);
1d4a9c17 BN	261	mdelay(pm_test_delay * 1000);
a9d70523 RW	262	return 1;
	263	}
	264	#endif /* !CONFIG_PM_DEBUG */
	265	return 0;
	266	}
	267
	268	/**
55ae4519	269	* suspend_prepare - Prepare for entering system sleep state.
a9d70523	270	*
55ae4519 RW	271	* Common code run for every system sleep state that can be entered (except for
	272	* hibernation). Run suspend notifiers, allocate the "suspend" console and
	273	* freeze processes.
a9d70523	274	*/
7e73c5ae	275	static int suspend_prepare(suspend_state_t state)
a9d70523	276	{
ea00f4f4	277	int error, nr_calls = 0;
a9d70523	278
8490fdf9	279	if (!sleep_state_supported(state))
a9d70523 RW	280	return -EPERM;
	281
	282	pm_prepare_console();
	283
ea00f4f4 LW	284	error = __pm_notifier_call_chain(PM_SUSPEND_PREPARE, -1, &nr_calls);
	285	if (error) {
	286	nr_calls--;
a9d70523	287	goto Finish;
ea00f4f4	288	}
a9d70523	289
bb3632c6	290	trace_suspend_resume(TPS("freeze_processes"), 0, true);
a9d70523	291	error = suspend_freeze_processes();
bb3632c6	292	trace_suspend_resume(TPS("freeze_processes"), 0, false);
03afed8b	293	if (!error)
a9d70523 RW	294	return 0;
a9d70523 RW	295
03afed8b TH	296	suspend_stats.failed_freeze++;
03afed8b TH	297	dpm_save_failed_step(SUSPEND_FREEZE);
a9d70523	298	Finish:
ea00f4f4	299	__pm_notifier_call_chain(PM_POST_SUSPEND, nr_calls, NULL);
a9d70523 RW	300	pm_restore_console();
	301	return error;
	302	}
	303
	304	/* default implementation */
52f5684c	305	void __weak arch_suspend_disable_irqs(void)
a9d70523 RW	306	{
	307	local_irq_disable();
	308	}
	309
	310	/* default implementation */
52f5684c	311	void __weak arch_suspend_enable_irqs(void)
a9d70523 RW	312	{
	313	local_irq_enable();
	314	}
	315
	316	/**
55ae4519 RW	317	* suspend_enter - Make the system enter the given sleep state.
	318	* @state: System sleep state to enter.
	319	* @wakeup: Returns information that the sleep state should not be re-entered.
a9d70523	320	*
3b5fe852	321	* This function should be called after devices have been suspended.
a9d70523	322	*/
3b5fe852	323	static int suspend_enter(suspend_state_t state, bool *wakeup)
a9d70523 RW	324	{
	325	int error;
	326
8490fdf9 RW	327	error = platform_suspend_prepare(state);
	328	if (error)
	329	goto Platform_finish;
a9d70523	330
2a8a8ce6	331	error = dpm_suspend_late(PMSG_SUSPEND);
a9d70523	332	if (error) {
22e09b33	333	pr_err("PM: late suspend of devices failed\n");
ce441011	334	goto Platform_finish;
a9d70523	335	}
a8d46b9e RW	336	error = platform_suspend_prepare_late(state);
	337	if (error)
	338	goto Devices_early_resume;
	339
2a8a8ce6 RW	340	error = dpm_suspend_noirq(PMSG_SUSPEND);
2a8a8ce6 RW	341	if (error) {
22e09b33	342	pr_err("PM: noirq suspend of devices failed\n");
a8d46b9e	343	goto Platform_early_resume;
2a8a8ce6	344	}
ebc3e41e	345	error = platform_suspend_prepare_noirq(state);
8490fdf9 RW	346	if (error)
8490fdf9 RW	347	goto Platform_wake;
a9d70523	348
08605acc ZR	349	if (suspend_test(TEST_PLATFORM))
	350	goto Platform_wake;
	351
7e73c5ae ZR	352	/*
	353	* PM_SUSPEND_FREEZE equals
	354	* frozen processes + suspended devices + idle processors.
	355	* Thus we should invoke freeze_enter() soon after
	356	* all the devices are suspended.
	357	*/
	358	if (state == PM_SUSPEND_FREEZE) {
bb3632c6	359	trace_suspend_resume(TPS("machine_suspend"), state, true);
7e73c5ae	360	freeze_enter();
bb3632c6	361	trace_suspend_resume(TPS("machine_suspend"), state, false);
7e73c5ae ZR	362	goto Platform_wake;
	363	}
	364
a9d70523 RW	365	error = disable_nonboot_cpus();
	366	if (error \|\| suspend_test(TEST_CPUS))
	367	goto Enable_cpus;
	368
	369	arch_suspend_disable_irqs();
	370	BUG_ON(!irqs_disabled());
	371
2e711c04	372	error = syscore_suspend();
a9d70523	373	if (!error) {
3b5fe852 MH	374	*wakeup = pm_wakeup_pending();
3b5fe852 MH	375	if (!(suspend_test(TEST_CORE) \|\| *wakeup)) {
bb3632c6 TB	376	trace_suspend_resume(TPS("machine_suspend"),
bb3632c6 TB	377	state, true);
a9d70523	378	error = suspend_ops->enter(state);
bb3632c6 TB	379	trace_suspend_resume(TPS("machine_suspend"),
bb3632c6 TB	380	state, false);
c125e96f	381	events_check_enabled = false;
67176736 RK	382	} else if (*wakeup) {
67176736 RK	383	error = -EBUSY;
c125e96f	384	}
40dc166c	385	syscore_resume();
a9d70523 RW	386	}
	387
	388	arch_suspend_enable_irqs();
	389	BUG_ON(irqs_disabled());
	390
	391	Enable_cpus:
	392	enable_nonboot_cpus();
	393
	394	Platform_wake:
ebc3e41e	395	platform_resume_noirq(state);
2a8a8ce6 RW	396	dpm_resume_noirq(PMSG_RESUME);
2a8a8ce6 RW	397
a8d46b9e RW	398	Platform_early_resume:
	399	platform_resume_early(state);
	400
2a8a8ce6 RW	401	Devices_early_resume:
2a8a8ce6 RW	402	dpm_resume_early(PMSG_RESUME);
a9d70523	403
ce441011	404	Platform_finish:
ebc3e41e	405	platform_resume_finish(state);
a9d70523 RW	406	return error;
	407	}
	408
	409	/**
55ae4519 RW	410	* suspend_devices_and_enter - Suspend devices and enter system sleep state.
55ae4519 RW	411	* @state: System sleep state to enter.
a9d70523 RW	412	*/
	413	int suspend_devices_and_enter(suspend_state_t state)
	414	{
	415	int error;
3b5fe852	416	bool wakeup = false;
a9d70523	417
8490fdf9	418	if (!sleep_state_supported(state))
a9d70523 RW	419	return -ENOSYS;
a9d70523 RW	420
8490fdf9 RW	421	error = platform_suspend_begin(state);
	422	if (error)
	423	goto Close;
	424
a9d70523 RW	425	suspend_console();
	426	suspend_test_start();
	427	error = dpm_suspend_start(PMSG_SUSPEND);
	428	if (error) {
9350de06	429	pr_err("PM: Some devices failed to suspend, or early wake event detected\n");
a9d70523 RW	430	goto Recover_platform;
	431	}
	432	suspend_test_finish("suspend devices");
	433	if (suspend_test(TEST_DEVICES))
	434	goto Recover_platform;
	435
3b5fe852 MH	436	do {
3b5fe852 MH	437	error = suspend_enter(state, &wakeup);
8490fdf9	438	} while (!error && !wakeup && platform_suspend_again(state));
a9d70523 RW	439
	440	Resume_devices:
	441	suspend_test_start();
	442	dpm_resume_end(PMSG_RESUME);
	443	suspend_test_finish("resume devices");
0cadc702	444	trace_suspend_resume(TPS("resume_console"), state, true);
a9d70523	445	resume_console();
0cadc702	446	trace_suspend_resume(TPS("resume_console"), state, false);
1f0b6386	447
8490fdf9	448	Close:
ebc3e41e	449	platform_resume_end(state);
a9d70523 RW	450	return error;
	451
	452	Recover_platform:
ebc3e41e	453	platform_recover(state);
a9d70523 RW	454	goto Resume_devices;
	455	}
	456
	457	/**
55ae4519	458	* suspend_finish - Clean up before finishing the suspend sequence.
a9d70523	459	*
55ae4519 RW	460	* Call platform code to clean up, restart processes, and free the console that
55ae4519 RW	461	* we've allocated. This routine is not called for hibernation.
a9d70523 RW	462	*/
	463	static void suspend_finish(void)
	464	{
	465	suspend_thaw_processes();
a9d70523 RW	466	pm_notifier_call_chain(PM_POST_SUSPEND);
	467	pm_restore_console();
	468	}
	469
	470	/**
55ae4519 RW	471	* enter_state - Do common work needed to enter system sleep state.
55ae4519 RW	472	* @state: System sleep state to enter.
a9d70523	473	*
55ae4519 RW	474	* Make sure that no one else is trying to put the system into a sleep state.
	475	* Fail if that's not the case. Otherwise, prepare for system suspend, make the
	476	* system enter the given sleep state and clean up after wakeup.
a9d70523	477	*/
93e1ee43	478	static int enter_state(suspend_state_t state)
a9d70523 RW	479	{
	480	int error;
	481
bb3632c6	482	trace_suspend_resume(TPS("suspend_enter"), state, true);
43e8317b RW	483	if (state == PM_SUSPEND_FREEZE) {
	484	#ifdef CONFIG_PM_DEBUG
	485	if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
a395d6a7	486	pr_warn("PM: Unsupported test mode for suspend to idle, please choose none/freezer/devices/platform.\n");
43e8317b RW	487	return -EAGAIN;
	488	}
	489	#endif
	490	} else if (!valid_state(state)) {
	491	return -EINVAL;
	492	}
a9d70523 RW	493	if (!mutex_trylock(&pm_mutex))
	494	return -EBUSY;
	495
7e73c5ae ZR	496	if (state == PM_SUSPEND_FREEZE)
	497	freeze_begin();
	498
2fd77fff	499	#ifndef CONFIG_SUSPEND_SKIP_SYNC
bb3632c6	500	trace_suspend_resume(TPS("sync_filesystems"), 0, true);
a9d70523 RW	501	printk(KERN_INFO "PM: Syncing filesystems ... ");
	502	sys_sync();
	503	printk("done.\n");
bb3632c6	504	trace_suspend_resume(TPS("sync_filesystems"), 0, false);
2fd77fff	505	#endif
a9d70523	506
a9215045	507	pr_debug("PM: Preparing system for sleep (%s)\n", pm_states[state]);
ef25ba04	508	pm_suspend_clear_flags();
7e73c5ae	509	error = suspend_prepare(state);
a9d70523 RW	510	if (error)
	511	goto Unlock;
	512
	513	if (suspend_test(TEST_FREEZER))
	514	goto Finish;
	515
bb3632c6	516	trace_suspend_resume(TPS("suspend_enter"), state, false);
a9215045	517	pr_debug("PM: Suspending system (%s)\n", pm_states[state]);
87186475	518	pm_restrict_gfp_mask();
a9d70523	519	error = suspend_devices_and_enter(state);
87186475	520	pm_restore_gfp_mask();
a9d70523 RW	521
	522	Finish:
	523	pr_debug("PM: Finishing wakeup.\n");
	524	suspend_finish();
	525	Unlock:
	526	mutex_unlock(&pm_mutex);
	527	return error;
	528	}
	529
	530	/**
55ae4519 RW	531	* pm_suspend - Externally visible function for suspending the system.
55ae4519 RW	532	* @state: System sleep state to enter.
a9d70523	533	*
55ae4519 RW	534	* Check if the value of @state represents one of the supported states,
55ae4519 RW	535	* execute enter_state() and update system suspend statistics.
a9d70523 RW	536	*/
	537	int pm_suspend(suspend_state_t state)
	538	{
bc25cf50 RW	539	int error;
	540
	541	if (state <= PM_SUSPEND_ON \|\| state >= PM_SUSPEND_MAX)
	542	return -EINVAL;
	543
	544	error = enter_state(state);
	545	if (error) {
	546	suspend_stats.fail++;
	547	dpm_save_failed_errno(error);
	548	} else {
	549	suspend_stats.success++;
2a77c46d	550	}
bc25cf50	551	return error;
a9d70523 RW	552	}
a9d70523 RW	553	EXPORT_SYMBOL(pm_suspend);